Updated 10:09 a.m. | State Sen. Toi Hutchinson will drop out of the the 2nd District special election Sunday and back her fellow Democrat, Cook County Chief Administrative Officer Robin Kelly, according to local newsreports.

Hutchinson's departure comes less than 48 hours after New York Mayor Michael Bloomberg's PAC unleashed a television ad criticizing her position on gun control.

Bloomberg's Independence USA PAC spot also endorsed Kelly — part of the $2 million his group plans to spend on this race. Local Democrats view Kelly as the front-runner in this race, and Hutchinson's withdrawal only helps to cement her former foe's top status.

In the first several weeks of the special election to replace former Rep. Jesse L. Jackson Jr., D-Ill., Hutchinson ran an able campaign. She had good fundraising and a noteworthy campaign team.

But Hutchinson faltered when gun control came to dominate this race. In previous runs, Hutchinson boasted support from Second Amendment rights groups like the National Rifle Association.

"So far the gun issue has been the number one issue in the campaign, and that's worked to Robin's benefit," a Democratic consultant involved in the special election told CQ Roll Call prior to Hutchinson dropping her bid.

"Toi needed to make voters question Robin's ethics, but at this point that hasn't happened," the strategist added. "To a large extent the issue landscape has helped generate momentum for Robin, but you never know what will happen in a special election."

Alderman Anthony Beale and former Rep. Debbie Halvorson fill out the top tier of the Democratic field. This is a safe Democratic district, so the winner of the Feb. 26 primary will most likely come to Congress.

Update 10:09 a.m.

Kelly's campaign released a statement from Hutchinson including her endorsement.

“I am ending my campaign for Congress today and throwing my support behind Robin Kelly," she wrote. "I urge those who have been supporting me to now work hard for Robin over the next 9 days."

"In the wake of horrendous gun related crimes all across our country, I agree with Robin that we need to stand together to fight gun violence, but Debbie Halvorson been wrong headed in her refusal to moderate her views on banning dangerous assault weapons," she added.